17 major avoidance principles in the steel pipeline construction

1. The small steel tube makes the big tube: the small tube is easy to bend and the cost is low.
2. Branch pipes to main steel pipes: branch pipes are generally smaller in diameter. See Article 1 for the reasons for avoidance. Also, the scope and importance of branch steel pipes are not as important as that of the main pipes.
3. Pressure tube to pressureless steel tube (pressure-flow tube to gravity flow tube): The pressureless steel tube (or gravity flow tube) changes the slope and flow direction, which has a greater impact on the flow.
4. Water supply steel pipe and drain steel pipe: In addition to the above-mentioned reason 3, the diameter of the drainpipe is usually large and there are many impurities in the water.
5. Normal temperature steel pipes should be high (low) temperature pipes (cold water pipes should be hot water pipes, non-insulated pipes should be insulated pipes): Exhaust should be considered when the temperature is higher than normal temperature; condensation prevention and insulation should be considered when the temperature is lower than normal temperature.
6. Low-pressure steel pipes let high-pressure steel pipes: high-pressure steel pipes are expensive and require high strength.
7. The gas steel pipe makes the water steel pipe: the power consumption of water flows is large.
8. The metal tube makes a non-metal tube: a metal tube is easy to bend, cut, and connect.
9. General ducts let ventilation ducts: The ventilation ducts are bulky and difficult to bend.
10. Small valves make more valves: consider factors such as installation, operation, and maintenance.
11. Simple construction avoids difficult construction: This is considered from the aspect of avoiding increased installation difficulty.
12. Small engineering volume leads to large engineering volume: This is considered from the aspect of avoiding increasing installation engineering volume.
13. Steel pipelines with low technical requirements let steel pipelines with high technical requirements: this is considered from the aspect of avoiding the difficulty of increasing technical requirements.
14. The convenience of fewer overhauls makes it more and inconvenient: this is considered from the perspective of later maintenance.
15. Non-main steel pipelines avoid main steel pipelines: This is considered from the aspect of functional importance.
16. Temporary steel pipeline avoidance steel pipeline: This is considered from the perspective ofsteel   pipeline services life.
17. Newly-built steel pipelines avoid the already-built steel pipelines: this is considered from the aspects of reducing cost, engineering volume, and construction difficulty.